(a) Field of the Invention
This invention relates to a flashlight structure, and more particularly to a flashlight structure with a heat-dissipation device.
(b) Description of the Prior Art
Flashlights are extremely useful as portable lighting devices. There are several types of the flashlights provided according to the requirement, wherein a flashlight with a high-power luminary is one of those developed directions. On the other hand, a light emitting diode (LED) is well considered as a luminary. Being compared with the conventional luminary, for example a pilot lamp, fluorescent lamps, an incandescent lamp and so on, the LED has several features of small volume, low heat-produced, low power consumption, long use life, high responding speed, environmental-protection, thin and compact. However, LED flashlight always has to include a LED array to put in use. Recently, high-power LED is developed and well down. Therefore, a high-power LED flashlight has practical applications. Unfortunately, a high-power LED would produce a lot of heat, and that will be a serious problem to limit its usefulness. The problem has to be solved.
Most flashlights comprise a cylindrical housing containing one or more batteries therein, a cap on one end of the housing containing a light source, such as a bulb or light emitting diode, a reflector and a lens cover over the light source. The light source is electrically connected in series with the batteries so that it can be turned on and off. Generally, some type of switch is provided to turn the light source on and off. To achieve more power and a stronger light, the flashlight is generally provided with two or more batteries in series and/or larger size batteries. The larger the number of batteries used to obtain an increase in power, the larger the housing that is required. Please refer to FIG. 1. It illustrates a high-power LED flashlight according to the prior art. As being shown in FIG. 1, the high-power LED flashlight structure includes a high-power LED luminary 11, a reflector 12, a base 13, a protecting housing 14, a lens cover 15, a casing having a power source 161 and a switch 17. Meanwhile the high-power LED luminary 11 is disposed on the base 13 and has the reflector 12 passing therethrough, wherein the reflector 12 is used for collecting and reflecting the light produced by the high-power LED luminary 11, and the base 13 is used for conducting with the power source 161. A user can decide to turn on or turn off the flashlight by means of controlling the switch 17. The protecting housing 14 and the casing 16 include the thread of screws for engaging with each other. When the protecting housing 14 and the casing 16 are combined together, the high-power LED luminary 14, the reflector 12 and the base can be included and fixed in the protecting housing 14. Furthermore, the protecting housing has an opening for passing the light therethrough, wherein the flashlight structure further includes a lens cover 15 for protecting the high-power LED luminary 11 completely.
Please refer to FIG. 2. It illustrates a cross-section structure of a high-power LED flashlight according to the prior art. As being shown in FIG. 2, the high-power LED luminary 11 is fixed on the base 13 and has the reflector 12 passing therethrough, and the base 13 is further fixed in the protecting housing 14. Meanwhile, the high-power LED luminary 11 has a cathode electrode connecting with the base 13, and an anode electrode connected to a conducting point 13, wherein the conducting point 131 is isolated with the base 13 via an isolating piece 132. When the protecting housing 14 and the power source 16 are combined together, the conducting point 131 can contact with a positive terminal 1611 of the power source (battery) 161 of the casing 16. The base 13, the protecting housing 14, and the casing 16 are formed by aluminum alloy. Accordingly, after the flashlight is assembled, the high-power LED luminary can be controlled via the switch of the bottom.
The prior high-power LED flashlight structures are easy to be operated and assembled, but they cause the heat-dissipating problem in application. The use life of the LED is related to the temperature of the environment near the LED chip. Hence, it is important to control the temperature for the LED. Usually, the LED will transform 10% electricity into light and 90% electricity into heat, but the prior art can't remove the heat produced by the luminary efficiently, thereby the use life of the flashlight is decreased. Therefore, it needs to provide a flashlight structure with a heat-dissipating device, which is capable of preventing the high-power luminary from break, being assembled easily and efficiently, and can rectify those drawbacks of the prior art and solve the above problems.